Improving Xanthophyllomyces dendrorhous astaxanthin stability by encapsulation using a fructan matrix

Abstract

Astaxanthin is a pigment and powerful antioxidant that has gained a high interest as a bioactive food constituent, compared to other carotenoids. Xanthophyllomyces dendrorhous is one of the main producers of non-esterified (3R, 3´R)-astaxanthin, which is highly assimilable, however, its stability is low (half-life of 19 h at 30 °C). Microencapsulation has emerged as an interesting technique to increase astaxanthin stability, maintain its bioactivity and preserve interesting characteristics. In the present study, a bio-based food constituent fructan (inulin and/or agave fructans) containing microencapsulated non-esterified (3R, 3´R)-astaxanthin produced by X. dendrorhous and extracted using supercritical CO2 was obtained and characterized. Using this technique, astaxanthin stability increased 26-fold compared to the free molecule. In addition, it was also demonstrated that microencapsulated astaxanthin using inulin as a matrix (91.3 ± 0.56 encapsulation efficiency), the capsules resulted well defined (size 2.66 ± 1.08 µm) and maintained their color tone (>70%) for at least 240 h under oxidation conditions. This work obtained a new bio-based stable fructan-astaxanthin microencapsulated food constituent with presumably increased solubility (82.00 ± 5.01 water solubility; size: 2.66 ± 1.08 µm) and bioavailability.